What is your strategy for debate him?
Will there be a moderator?
Can you set down some ground rules?
One of the first things you should be weary of is whether or not the person you are arguing with will argue in good faith. I'm not going to lie, I think its going to be extremely frustrating for you. We can see how all the liberals act in an argument as soon as you start dropping red pills (Appeal to emotion, Kafkatrap, No true scotsman, etc).
They are going to play the race card HARD(Ask them why more white people are killed by police, and how majority of black men are killed by black men), they are going to play the oppression card (Ask them why the president is a black man). If they attempt to claim the moral high ground, ask them why the outlet for oppression is to burn down black businesses and black neighborhoods. Lead this further in by asking why 3/4 of the people arrested in the Charlotte riots have out of state ID, and how much more havoc they caused then should have been possible.
Be calm, let them shout over you (because as soon as they start shouting, they lose the moral high ground. Ask them why they don't want to listen, even though you already listened to his/her side of the argument). If they set a goalpost, do not let them move it at all.
I'm not going to lie to you OP, the deck is already stacked against you even if you have all the facts. You are dealing with a bunch of entitled millennials who would rather listen to the heart rather than the facts. Your victory point here is not to win against the libtard, (because you are "part of the systematic oppression that the white man has to set up) but to get at least a couple of people in the audience started on the path of doubt. Defeating him is impossible because he is too ingrained in his beliefs. What you want to do is start chipping away at the foundations.
I would hesitate to mention any form of nigger inferiority at all on the sole basis most normies throw up a mental shield against whatever you have to say if you even remotely talk about white superiority.
They will do their best to insult you and call you a racist. Just smile and ask them for proof. If they laugh and say your facts are racist, smile, thank them for their time, and walk away. Remember, you have absolutely nothing to lose, so there's no need to get butthurt if they start throwing insults (And honestly, if you get butthurt over a few words, your home is tumblr, not /pol)
REMEMBER: Stay CALM, stay COLLECTED. THANK THEM afterwards for debating. SHAKE THEIR HANDS if they are willing. BE CIVIL. Use subtle redpills. Most normies are not ready for the truth. And fucking SMILE (smug if you can manage it). If anyone looks like they are interested afterwards, talk/chat with them. Give them an email. Maybe give them a redpill website (That's not /pol. They aren't ready yet).
Start them on the path op.
Good luck.
Pic unrelated.